EXFO FTB -5240S/5240BP Optical Spectrum Analyzer - Manual (Page 228)

Setting Up the Instrument in EDFA Mode
222 FTB-5240S/S-P/BP
Setting Up EDFA Analysis Parameters

Peak detection level (dBm): minimum power level from where the
peak can be considered as a signal.

RBW for OSNR (nm): indicates the resolution bandwidth selected
for the OSNR calculation. This parameter is generally set to 0.1 nm
to allow for a common basis of comparison between different
OSAs having different effective resolutions. The instrument’s RBW
value is written below the graph. This parameter does not actually
have an effect on the acquisition, but is only a normalization factor
used to provide the OSNR value in a standardized manner.

Input wavelength offset (nm): offset value applied on the input
wavelength. This does not replace a calibration performed at
EXFO, but it can help you temporarily sharpen the specifications if
you have determined that, for example, your modules are used
beyond the normal allowed. Entering a value in THz is not possible.
When an offset is applied, it is indicated at the bottom of the graph
( ).

Input power offset (dB): offset value applied on the input power.
This does not replace a calibration performed at EXFO, but it can
help you achieve the specifications if you have determined that, for
example, your modules are used beyond the normal allowed.
When an offset is applied, it is indicated at the bottom of the graph
(P
).
To edit the power offset value as a tap percentage, press the Edit %
button.
The percentage value entered in Edit percentage will be
converted to a corresponding equivalent value in dB.